Step 1: Prepare the Chocolate Crust

1. Preheat oven to 325°F (163°C). Grease a 9-inch springform pan.
2. In a bowl, mix chocolate cookie crumbs, melted butter, and sugar until well combined.
3. Press the mixture firmly into the bottom of the springform pan.
4. Bake for 8-10 minutes until set. Let it cool while preparing the cheesecake filling.

Step 2: Make the Cheesecake Filling

1. In a large bowl, beat cream cheese and sugar until smooth and creamy.
2. Add eggs, one at a time, mixing on low speed to avoid overbeating.
3. Stir in sour cream and vanilla extract until just combined.
4. Divide the batter in half. In one half, fold in melted German chocolate for a chocolate layer.
5. Pour the plain cheesecake batter over the crust, then gently layer the chocolate cheesecake batter on top.

Step 3: Bake the Cheesecake

1. Use a water bath (bain-marie): Wrap the cheesecake pan in aluminum foil and place it in a large roasting pan. Fill the roasting pan with hot water until it reaches 1 inch up the sides.
2. Bake at 325°F (163°C) for 55-60 minutes, or until the center is slightly jiggly but the edges are set.
3. Turn off the oven, crack the oven door open slightly, and let the cheesecake cool for 1 hour inside the oven.
4. Refrigerate for at least 4 hours or overnight before adding the toppings.

Step 4: Make the Chocolate Ganache

1. Heat heavy cream in a saucepan until it begins to simmer.
2. Remove from heat and pour over chopped chocolate. Let sit for 1 minute, then stir until smooth.
3. Let the ganache cool slightly before pouring a layer over the cheesecake. Refrigerate to set.

Step 5: Make the German Chocolate Topping

1. In a saucepan over medium heat, melt butter, then stir in brown sugar and evaporated milk.
2. Whisk in egg yolks and cook until the mixture thickens (about 5 minutes).
3. Remove from heat and stir in vanilla extract, shredded coconut, and chopped pecans.
4. Let the topping cool slightly, then spread over the set ganache layer on the cheesecake.

Step 6: Garnish & Serve

1. Pipe chocolate whipped cream around the edges of the cheesecake.
2. Sprinkle with chocolate shavings and additional chopped pecans for an elegant finish.
3. Slice, serve, and enjoy the ultimate German Chocolate Cheesecake experience!